Sensitive teeth

There are many reasons that one or more teeth can be sensitive. It is important to see a dentist if you have a tooth that is sensitive to cold, hot or sweet foods or drinks. This may be a sign of tooth decay or tooth erosion. It is important to make sure there is no tooth decay or other conditions that are making the teeth sensitive.

Symptoms

Tooth sensitivity will often feel like a short, sharp pain. The pain occurs when the tooth is exposed to a stimulus. The pain will usually go away once the stimulus is removed. Examples of a stimulus that can cause pain in sensitive teeth include:

• hot foods or drinks,
• cold foods or drinks,
• cool air, or
• gentle touch, for example from a toothbrush.

Sensitivity can occur in only one or two teeth, or it can affect multiple teeth.

What causes sensitive teeth?

Teeth often become sensitive when the outside layer of teeth that provides protection is worn away or lost. Tooth enamel protects the part of the tooth that we can see inside the mouth, called the crown. The tooth root/s are protected by a layer of tooth structure called cementum and the gums around the tooth. These protective layers do not have feeling. They protect the inside layer of the tooth called dentine. The nerves inside the tooth extend into the dentine giving it feeling. 

If the enamel or cementum is worn away and no longer protecting the dentine, this can cause the tooth to become sensitive. When a stimulus directly contacts the dentine, it may cause pain from the nerve. This may be diagnosed as ‘dentine hypersensitivity’. It is a very common complaint from patients at the dentist.

Getty Images.
 

Some common causes of tooth sensitivity

• Enamel worn away from tooth erosion due to regularly eating or drinking acidic foods and drinks.
• Gums shrinking away from the teeth exposing the tooth root/s that are covered by the cementum. Cementum is not as strong as tooth enamel and can wear away more easily uncovering the dentine. 
• Teeth grinding or clenching teeth at night whilst sleeping.
• Conditions that affect the teeth when they are developing. This can cause weakened tooth structure, for example enamel hypoplasia.

Teeth can sometimes be sensitive after dental treatment. This is usually temporary. It may last for a few days or up to two weeks. It can occur after treatments such as a professional teeth cleaning (known as a scale and clean), fillings, crowns and teeth whitening. If the sensitivity continues or turns into pain, return to see your dentist. 

Caring for sensitive teeth

It is important to see your dentist if you have one or more sensitive teeth. They will examine the teeth to find the cause of the sensitivity and let you know how to treat it. At your appointment, your dentist may discuss your eating, drinking and oral hygiene habits. It is important for them to be aware of lifestyle factors such as regularly drinking soft drinks, which may be causing your sensitive teeth.
 

Dental treatment

If the tooth sensitivity is due to tooth decay or fillings already present in the tooth that are starting to break down, this needs to be treated. After treatment, the sensitivity should go away. The sensitivity may get worse and turn into bad pain if these issues are not treated.

Sensitive teeth that have dentine that is exposed may be treated by placing a covering over this dentine. This covering could be a filling or a layer of fluoride gel. This fluoride is stronger than your daily toothpaste. Research has shown that these gels can help decrease dentine sensitivity.
 

Toothpaste

Some toothpastes are made for the specific purpose of treating sensitive teeth. These are called desensitizing toothpastes. Ingredients that help to treat tooth sensitivity work by two main methods.

1. The nerves in the teeth are soothed so they no longer respond to the stimuli. 
2. A barrier is created over the sensitive dentine stopping it from responding to stimuli.

Ingredients in desensitizing toothpaste that are added to treat sensitive teeth include potassium nitrate, arginine and calcium carbonate, strontium chloride, stannous fluoride, and calcium sodium phosphosilicate.

If tooth decay has developed and is causing your tooth sensitivity, using desensitizing toothpaste will not treat the decay, this must be done by a dentist.

Preventing sensitive teeth

Good oral hygiene is your best defence against tooth sensitivity.

• Keep good oral hygiene by brushing twice per day with fluoride toothpaste and flossing at least once per day.
• Do not apply too much pressure when brushing your teeth.
• Limit the amount of sugary or acidic drinks you consume, and do not brush your teeth straight after. Try to wait at least 60 minutes before brushing. Brushing too soon can lead to increased tooth wear.
• Drink plain tap water to stay hydrated. Adding citrus fruit, such as lemon, to your water and sipping it during the day can lead to tooth erosion and/or tooth sensitivity.